Find YouTube Channel ID
YouTube channels with a URL structure like https://www.youtube.com/c/USERNAME need additional action to get the correct channel ID.
You can use this tool to get the channel ID https://commentpicker.com/youtube-channel-id.php.
Alternatively, you can view the source code of the channel page and find either data-channel-external-id or externalId or channelId keywords. Their value will be the channel ID you're looking for.